Recent research findings indicate strong associations between sports participation and adolescent health-risk behavior; for example, compared to their peers, high school athletes are at lower risk for illicit drug use, cigarette smoking, and suicide but at higher risk for binge drinking and smokeless tobacco use. These associations are in many respects gender-specific; female athletes report less sexual risk-taking than nonathletes, whereas male athletes report more. The present R21 application will extend this research to explore the effects of athletic involvement on substance use and other problem behaviors among female and male college students, examine the longitudinal effects of high school sports on young adult problem behavior, and create comprehensive new measures of athletic involvement for use in future research. Two complementary research strategies are proposed. First, cost-effective, secondary data analysis will be conducted on the Family and Adolescent Study (FAAS), a six-year longitudinal study of Western New York youth and their families (N=699) which includes self-report data on athletic participation as well as alcohol, tobacco, marijuana and other substance use, sexual risk-taking, and depression. Second, informed by findings from the FAAS, the Athletic Involvement Pilot Study (AIPS) will draw on focus group and questionnaire responses of Western New York undergraduate college student-athletes in order to design and pilot test new, multidimensional measures of athletic involvement. In its final round, the AIPS will collect data to test hypotheses about the gender-specific relationships between high school and college athletic involvement and substance use, sexual risk-taking, depression, and suicidality. This research will also serve as a basis for the development of a theory-driven R01 proposal examining factors associated with sports participation, gender, and substance use. The research has the overall aim of establishing more effective prevention and intervention strategies for reducing young adult substance use and other related health-risk behaviors.